Figure 5. Schematic illustration of the importance of EDN1 in the maintenance of CVPs.

We proposed that EDN1 promotes the clonal expansion of CVPs. Given the appropriate stimuli, CVPs were able to differentiate towards all three cardiac lineages (cardiomyocyte, smooth muscle cell and endothelial cell) in vitro (<10 passages) while almost exclusively contributed to vascular lineages in vivo (>20 passages). This suggests that EDN1 primes the CVP towards a vascular lineage while WNT3A functions primarily to enhance their proliferation.